Calculating attachment fob type



May 3, 1938. c. H SAMPSON 2,116,285

CALCULATING ATTACHMENT FOR TYPEWRITERS Filed April 5, 1952 4 Sheets-Sheet 1 INVENTOR CHmzss/iJmPxu May 3, 1938. c. H. SAMPSON CALCULATING ATTACHMENT FOR TYPEWRITERS Filed April 5, 1932 4 Sheets-Sheet 2 f v INVENTOR CHARLES/7. .Shrmswv 4 5010!!!! ,Illllll .l r I- INVENTOR May 3, 1938 c. H. SAMPSON CALCULATING ATTACHMENT FOR TYPEWRITERS Filed April 5, 1952 4 Sheets-Sheet 3 IL-Pi-I IF m 4 7 71/1, rllllrllllll (Mme-.5 h. mesa/v May 3, 1938. c. H. SAMPSON CALCULATING ATTACHMENT FOR TYPEWRIT-ERS Filed April 5, 1952 4 Sheets-Sheet 4 INYENT OR CHARLES/i Slnmmv amaam aioas' S j PATENT OFFICE Charles H. Sampson, Rochester, N. 1. Application April 5, 1982, Serial No. 8,865

L y 8 Claim This invention comprises a calculating attachment for typewritingmachines and has for one of its objects to provide an attachment embodying a calculating mechanism which is complete in itself and can be operated separately and joint 1y with the.typewriting nmchine.

Another object of this invention is to so construct the attachment and its operating mechanism that its operation in combination with a Wwriting machine is not dependent on a predetermined position of the carriage or any other part of the typewriting machine.

A further object of the invention is to provide 'a mechanism for the attachment which allows is the amounts to be recorded and totalized in any desired position on any sheet, letter or bill placed in the typewriter.

Another object of the invention is to provide connecting means between the keys of the typewriting machine and the calculating attachment which are manually operated to have the typewriter keys operate the calculating mechanism and are automatically operated to disconnect the typewriter keys from the calculating mechanism a after each set up or the clearing of the calculating mechanism.

These and other objects of the invention will become more readily apparent from the detailed description thereof which .follows reference being had to the accompanying drawings in which Figure 1 is a front elevation of a portion of a conventional form of a standard typewriter with the calculating attachment mounted thereon, some of the keys of the typewriter and the corresponding keys of the calculating attachment being omitted from the figure.

Figure 2 is a vertical sectional view of the calculating attachment, the section being taken on the line 23-21: of Figure 1.

Figure 8 is a vertical sectional view of the calculating mechanism, the section being taken on the line 31-31: of Figure 1.

Figure 4 is a rear elevation of the calculating mechanism.

Figure 5' is avertical sectional view of the calculating mechanism partly broken away, the section being taken on the line Isa-5:1: of Figure 4.

Figure 6 is a horizontal sectional view of the calculating mechanism, the section being taken on the line 6:|:6:|: of Figure 4.

Figure 'l is a vertical sectional view of the key operating mechanism of the calculating attachment and a dlagrammatlcal sectional view of the typewriter to which it is attached.

Figure 8 is a front elevation of one of the digit rack bar assemblies.

Figure 9 is a longitudinal sectional view of the upper portion of the index pin carriage illustrating the friction springs which frictionally hold the index pins in place in the carriage and lock them in place therein.

In the several figures ofthe drawings like reference numerals indicate like parts.

The calculating attachment forming the subject matter of my present invention is adapted for use with any make ofstandard typewriter and when attached thereto transforms the typewriter into a calculating machine adapted for writing, listing, adding and multiplying without restriction as to how and where the writing and listing must be done on the sheet in the typewriter.

As illustrated in the several figures of the drawings, the mechanism of the calculating attachment is mounted on a vertical base plate I which extends across the front of the frame A of the typewriter where it supports the key operating mechanism and extends to one side of the typewriter frame A where it supports the calculating mechanism proper.

In Figure "I the calculating attachment is illustrated attached to a portion of a standard typewriter in which A represents the frame thereof, 13 one of the type bars which is connected by means of a suitable link mechanism D to the key lever C of one of the numeral keys E. F represents the platen of the typewriter which is adapted to turn and travel endways over the frame and carries the paper sheet or sheets on which the typewritten matter, as well as the amounts from the calculating attachment, are recorded. The typewriter mechanism may be any one of the well known standard types of typewriters and the attachment of the calculating mechanism does not in any way affect the operation of the typewriter.

As above pointed out, the mechanism of the calculating attachment is entirely supported on the vertical base plate I which, as illustrated in Figure 1. is fastened to one side of the front face of the frame A of the typewriter by means of a screw 2 and to the other side by means of one or more screws 8. On the base plate are provided the guide lugs or pins 4, 4 which are spaced vertically to support and guide the horizontal cam slides I, t, I, I, 9, III, II-, I2, I! and II In addition to the vertically spaced guide lugs or pins 4, l, horizontally spaced guide lugs or pins l5, II are provided on the base plate I to guide the vertical cam slides l5, l6 which operate the horizontal cam slides and carry at the top the keys Each of the vertical cam slides has a slightly yielding spring connecting member l3 pivotally fastened to the bottom thereof and each of these connecting members has a dog l9 formed thereon which is adapted to engage with the key levers C as will hereinafter be described. The dogs l9 are movably attached to the shift bar 20 and for this purpose are provided with a slot 2| into which engages the pin 22 carried by the shift bar 20. The shift bar is mounted to slide on the vertical base plate I and is supported thereon by means of the pins 23 and 24 which engage into suitable slots 25 and 26 in the shift bar so as to support the shift bar on the base plate I and guide it in a straight line horizontal movement thereon. The shift bar may be moved manually in either direction by means of the bell crank lever 21 which is pivotally mounted on the base plate I at 28 and is provided with a key 29 on the free end thereof. The connection between the bell crank and the shift bar is provided by a pin 30 which is carried on the shift bar 20 and engages into the slot 3| provided in the bell crank lever 21.

In depressing the key 29, the bell crank lever is rocked and moves the shift bar 20 to the left in Figure. 1 carrying with it the pins 22 which swing the spring connecting members IS on the lower end of the vertical cam slides I6 and move the dogs I9 thereof behind the vertical portion of the key levers C.

The vertical portion of each of the key levers C is provided at the rear, with a lug 32 so that when a numeral key E is depressed after the dogs I!) have been moved behind the key levers, as above described, the lug of its key lever engages a dog l9 and moves its connecting member is and the vertical cam slide IE, to which the connecting member is attached, during part of the movement of the key lever which is being depressed by the numeral key. In this way each of the numeral keys E of the typewriter, when depressed, operates a corresponding vertical cam slide IS on the calculating attachment when the shift bar 20 has been operated by the key 29 to provide the connection between them, as above described, and moves this vertical cam slide downwardly in a vertical movement.

When it is desired to operate the calculating mechanism without operating the numeral keys of the typewriter in order to make a calculation without recording it, key 29 is raised to move the shift bar to the right and swings the dogs |9 to the right of the key levers so that they no longer are engaged by the lugs 32 thereof. The calculating mechanism, instead of being operated by the numeral keys of the typewriter, is then operated by means of the keys which are carried by the vertical slide bars at the top thereof.

Each of the vertical cam slides I6 is provided with a .pair of cam lugs 33 and 34 of which cam lug 33 engages one of the horizontal cam slides 5 to l3 inclusive,'while cam lug 34 passes thru the cam slots 35 provided in the horizontal cam slide M. In addition to the cam lugs 33 and 34, each of the vertical cam slides is also provided with a. stop lug 38. The horizontal cam slides 5 to |3 inclusive are each provided with a lug 31 which is located on the right hand side of the vertical cam slides and cooperates with the cam lugs 33 thereof so that when these cam slides are moved downwardly, each vertical cam slide moves a particular horizontal cam slide to the right.

While each cam lug 33 thus moves one of the horizontal cam slides 5 to i3 inclusive to the right, the cam lug 34 operates the horizontal cam slide l4 and moves it to the left on the downward movement of any one of the vertical cam slides l6. After one of the vertical cam slides l3 has been depressed by either its own key I! or the numeral key E connected thereto, it is returned to its normal position by a spring 38 which has its center portion wound around a supporting pin 40 so that the free ends thereof can engage under the pins or lugs 39 of two successive cam slides and hold these cam slides in their elevated starting position or move them back into this position after they have been depressed as above pointed out. Stop pins or lugs 4|, provided on the base plate, engage behind the cam lugs 34 and line up the vertical cam slides in a uniform starting position. The stop lug 36 of each of the vertical cam slides is suitably spaced from the cam lug 34 and engages the stop pin or lug 4| on the downward movement of the vertical cam slides in order to limit their movements to the movement necessary for the operation of the horizontal cam slides by the cam lugs 33 and 34.

Each of the horizontal cam slides 5 to l3 inclusive carries at its outer left hand end a cam 42 as illustrated in Figure 6. These cams operate to rock the rocking levers 43 which depress the index pins 44 for the setting of the digit rack bars 45 as will hereinafter be described. The horizontal cam slides 5 to l3 inclusive each carry a suitable lug 31 which is yieldingly held in its normal inoperative position against the side of the vertical cam slide just below the cam lugs 33 thereof. Springs 41 and 48 are mounted on the base plate I and their ends engage either a lug 43 on the horizontal cam slides or the free ends of one of these bars in order to yieldingly force the horizontal cam slides to the left in Figure 1- while their lugs 31 engage the side of the vertical cam bars below the cam lugs 33. When one of the vertical cam slides is therefore depressed either by means of its own key H or a numeral key E of the typewriter, the cam lug 33 thereof forces the lug 31 to the right in Figure 1 and shifts its corresponding horizontal cam slide against the pressure of one of the springs 41 or 48. In so doing the cam 42 at the end of the horizontal cam slide moves under the end of the rocking lever 43 and rocks this lever on its fixed vertical pivot pin 43A so that its opposite end engages one of the index pins and forces it into the carriage 53 on one side thereof. The opposite end of the pin thus operated by the rocking lever is forced away from the other side of the carriage and projects into the path of one of the digit rack bars 45 as will hereinafter be described.

In this way each of the nine keys ll of the calculating attachment and the nine of the numeral keys E of the typewriter on which the calculating attachment is mounted, operate one of the index pins 44 on the operation thereof.

The index pins 44 are mounted in a sliding carriage 50 which comprises a pair of vertical plate members suitably spaced apart, one of which is provided at the top with a projection 5| which is guided by a suitable guide member 52 located above the carriage 50 as illustrated in Figures 1 and 3. This same vertical plate member of the carriage 50 is provided near the bottom with lugs 53 and 54 thru which passes the guide bar 55. In this way the carriage 53 with itsindex pins 44 is supported to slide back and forth in the guide member 52 at the top and on the guide bar Bl at the bottom.

Movement is imparted to the carriage II by means of the spring I. This spring is anchored with one end to the bracket 51 and with its other end to the lever arm II which is keyed to the rock shaft IO. The upper end of the lever arm is connected to the outer end of the index pin carriage by means of the link OI. In order to provide a step by step movement for the carriage and a1- low the carriage to move only when one of the keys is operated, an escapement is provided which is operated on the operation of each of v The horizontal cam slide carries a cam II which,

when shifted to the left in Figure l, depresses the arm I! and rocks the shaft N. This in turn swings the arm 04 carried on the shaft is so that the dog Bl thereof engages into one of the slots 0. provided in the escapementbar ll while the dog ll moves out of this same slot and permits the carriage to be drawn to the left by the spring I until the end of the slot into which the dog has been engaged has reached the dog ll. When the key which has been depremed is released, the horizontal cam slide moves back so that the cam I allows the arm 02 to rock upwardly and raise the arm 84 so that the dog It disengages itself from the slot in the escapement bar 01 while the dog Cl engages into the succeeding slot and allows the carriage to be drawn another short distance until the end of the next slot reaches the dog I and is arrested thereby. Every time one of the keys is depressed, the carriage is thus allowedto move a distance equal to the distance between two consecutive index pins ll so that the operation of the next key will engage an index pin located in the succeeding vertical line of index pins in the carriage N. a

The index pins have part of their intermediate body portion reduced in diameter and a series of bow springs III are placed between the upright plate members of the carriage BI and encircle in a serpentine path the reduced sections of the horizontal lines of consecutive index pins in order to make frictional contact therewith to frictionally hold the index pins in the position into which they have been moved by the rocking levers ll. These springs also serve as keys which lock the index pins into the carriage andprevent them from entirely moving out therefrom in'either direction.

While the index pins have been set up by the keys, the carriage has been moved so that the operated index pins will form stops for the digit rack bars II on the downward movements thereof. Each digit rack bar is adapted to rotate a counterwheel A with which it is brought into mesh on its return movement from contact with one of the set up index pins. The digit rack bars 4| are moved to engage the index pins by the operation of the operating lever I! which is keyed to the shaft 13. .This shaft carries the arm II at the back of the base plate I as illustrated in Figuretwhichisconnectedbyalink 'l ltothe vertical slide carriage II. The carriage carries two racks-1.1 and "at the back thereof which mesh with the pinions I! and .0 respectively and rotate these pinions and with-them the shaft II on which they are keyed for a purpose that will presently appear.

The carriage II is provided with suitable side members I! and 03 (see Figures 3 and 6) and in each of these side members is provided an elongated slot 84 between which the supporting bar II is suspended by means of two suspension springs I6 and II. The bar 85 supports the lower bifurcated ends of the slides 09 which carry at their tops, lugs ll between which and the fixed lugs II are stretched the springs 02 as shown in Figure 3, one for each of the nine slides 80. These springs hold the slides 89 yieldingly against the supporting bar It and move with this bar when it is moved by the operation of the operating lever 12. Each of the digit rack bars ll is mounted on one side of one of the slides 80 as illustrated in Figures 3 and 8. For this purpose each .digit rack bar II is provided with a pair of rearwardly extending extensions II and M which are provided with the slots 98 and 0' respectively and into these slots engage the pins l1 and II respectively to guide and hold the digit bars or racks ll in a short straight line movement on the slides 89. A spring 80 is stretched between the lug ll. provided on the rearward extension '4 of each digit bar orrack {I and a pin lill carried by the slide I! on which this digit bar or rack is mounted. In this way each digit bar or rack I has a predetermined lost motion on its slide 80.

When the carriage It is pulled down on the operation of the lever 12 it does not disturb the position of the supporting shaft ll until the carriage has been moved a distance equal to the length of the slots 84 provided in the sides thereof. This lost motion of the carriage is transmitted to the shaft ll to operate means for rocking the counter wheels in and out of mesh with the digit bars or racks and also for operating locking means which prevent the operating lever 12 from returning to its normal starting position unless the lever has first been given its full predetermined movement. The latter locking means comprises a mutilated ratchet wheel II! which is keyed to the end of the shaft II and cooperates with a spring operated pawl I I! which is pivotally mounted below this ratchet wheel and is held by the spring I to normally project into the mutilated or cut out portion of the ratchet wheel. When therefore the shaft is rotated by the movement of the carriage I. on the downward movement of the handle ",the pawl is swung toone side and consecutively engages between the'ratchet teeth of the ratchet wheel to keep it from turning back untfl a complete revolution of the ratchet wheel has been made and the pawl again projects into the cut away periphery thereof. When the handle I! is released the spring "A (see Figure 1) draws it back to its starting position and during this later movement the shaft is rotated in the opposite direction so that the ratchet wheel swings the pawl to the opposite side to consecutively engage between the ratchet teeth to keep it from turning back until the ratchet wheel has made a complete revolution in the opposite direction and the pawl again projects into the cut awayportion thereof. 1

In its movement to operate the calculating mechanism after it has been set up by the keys thereof or the keys of the typewriter. the operating lever 12 also throws out the connection between the keys E of the typewriter and the vera shoulder I06 provided on the upper edge thereof and when the shift bar is shifted to the left in figure 1 on the operation of the key 29 to bring about the connection between the vertical slide bars and the typewriter keys E, the shoulder I06 is moved to the left and located below the cam I01 while the end of the arm passes thru a suitable opening in the side wall of the casing (see Figures 1 and 2). This cam has two cam lugs I08 and I09. Of these, cam lug I08 normally engages the-outer end of the extension arm I05 and holds the shoulder I06 thereof away from the cam lug I09 when the handle 12 is in its normal inoperative position. As soon as the handle is depressed the cam lug I08 moves away from the end of the extension arm and permits it to swing up so that the shoulder I06 thereof will engage behind the cam lug I09 after the handle 12 has been completely operated. If the shift bar 20 has been moved to connect the typewriter keys E with the calculating mechanism, the shoulder I06 of its extension arm is located approximately below the vertical center line of the cam I01 so that on the return of the handle 12 by the spring 12A, the cam lug I09 engages the shoulder I06 and forces the extension arm back to the right in Figure 1- and shifts the dogs I! to one side of the key levers to keep their keys from operating the calculating mechanism until the connection has again been made by shifting the shift bar to the left on the depression of the key 29.

For the purpose of keeping the operating lever from returning the shift lever and breaking the connection between the typewriter keys and the calculating mechanism, a cam I10 is mounted on the inside of the casing surrounding the calculating mechanism. This cam may be manually operated torest on the top of the end of the extension I 05 of the shift bar 20 and hold this extension so that lug I09 of cam I01 cannot engage the shoulder I06 and 'move the shift bar back.

To automatically return the carriage 50 with its index pins to its starting position in order to clear the mechanism on the return movement of the operating lever 12, the shaft 59, on which the lever arm 58 is mounted, has the segmental gear IIO keyed thereto at the back of the base plate I as illustrated in Figure 4. This segmental gear meshes with the segmental gear III carried on the shaft H2 and segmental gear IIO rotates the segmental gear III on the movement of the lever arm 58 as it shifts the index pin carriage 50. On the periphery of the segmental gear III is provided a lug which cooperates with the latch dog H4 carried by the carriage 16 and depending therefrom as illustrated in Figure 4. The latch dog H4 is provided with a slot II5 thru which passes the pivot pin II6 mounted on the carriage 16 to support the latch dog thereon. As the" carriage is pulled down by the operation of the lever 12, the pivot pin moves down in the slot II5 until it reaches the end of the slot. A further downward movement of the carriage to the end of its downward movement by the lever 12 moves the latch dog with it to have its hook shaped member II1 engage under the cam lug I53 so that when the latch dog III is raised on the return movement of the carriage 16, the engagement of the dog II1 with the lug III of the segmental gear III will rotate the gear and turn this gear and the segmental gear II 0 with its shaft 59 and the lever arm 58 back to its starting position. The return of the lever arm in this manner moves the index pin carriage 50 back to its starting position and any index pin which has been set by the keys and projects from back of the carriage 50 is forced back into the carriage to again project from the front of it as the pin slides past the angular cam surface II8 of the fixed cam member H9.

For the purpose of locking the latch dog III out of engagement with the cam lug II3 of the segmental gear III when it is desired to perform a multiplication by a repeated addition of the same set up, the slide I20, with its outwardly projecting flange I2I, is moved to the left In Figure 4 to engage and hold the lower end of the latch dog away from the cam lug I I3. The latch dog is then raised on the return movement of the carriage 16 without returning the index pin carriage 50 to its normal starting position and a repeated operation of the operating lever 12 will cause a repeated addition of the original set up of the index pins.

The latch dog is locked out by means of the repeat lever I22 which is pivoted at I23 and with one end projects into a suitable opening in the slide I20 while the other end projects to the front of the attachment and has the handle I24 formed thereon with which it can be shifted to move the slide either into or out of engagement with the latch dog. In order to hold the repeat lever in the repeat or normal position, the front of the casing thru which the lever projects is provided with the offset notches I25 and I26 at the ends of the slot I25A in which the lever moves back and forth. The end of the lever I22 then engages into one of these notches at the end of each movement to one side or the other.

The digit bars or racks 45 are adapted to operate the counter wheels only on their return movement after they have been moved down against oneof the index pins. For this reason the counter wheels are mounted to rotate on the counter shaft I21 .which is suspended by a pair of arms I28 and I29 from the pivot shaft I30. The end of the counter shaft I21 is connected with the carriage 16 by a combination of toggle and rocking levers I3I, I32 and I33 which are so arranged that during the first part of the movement of the carriage before the supporting shaft 85 is moved by it to allow the digit bars to move, the toggle lever I33, in moving down with the carriage, rocks the rocking lever I32 which in turn forces the toggle lever I3I to the right in Figure 2 and swings the counter shaft I21 with its counters out of mesh with the digit or rack bars 45. The digit bars are then free to move down on the downward movement of the carriage 16 until their movement is arrested by an engagement with one of the index pins 44.

The carriage 16 is ready to return when all of the digit bars have been moved to their lowermost position'as governed by the set up of the index pins. In this lowermost position and during the first part of the upward movement, the spring I35, which connects the two toggle levers I3I and I 33, draws the counter shaft to the left in Figure 2 in order to bring the digit rack bars in mesh with the pinions I36 of the counter wheels 45. The return movement of the digit rack bars then rotates the counter wheels in accordance to their movement as governed by the set up of the index pins. I

For the purpose of clearing the mechanism that is moving the counterwheels to their starting position after the sum total has been registered by them, the clearing bar I31 is slightly shifted to the right in Figure 1. This clearing bar is an extension of the index pin carriage 50 and in the rear thereof facing the digitor rack bars 45 are provided a series of notches I55. A suitable opening in the side wall of the housing permits its end to pass thru the side wall on its movement to the left. The notches in the clearing bar are so arranged that on the starting position of the index pin carriage 50, they are held out of line with the digit or rack bars 45 and thus prevent these bars from moving downwardly. In order to allow these bars to be moved for the purpose of turning the counter wheels back to their normal starting position, the clearing bar is slightly moved to the right in Figure l by means of the cam I35 provided on the extension I40 of the toggle lever ISI. This extension I45 projects to the front of the calculating attachment and has the key I provided thereon. When therefore this key is depressed to rock the toggle link III, the cam I35 engages the end of the clearing bar and shifts it slightly to the right in Figure 1 until the notches I55 inthe clearing bar are in line with the digit or rack bars 45 and permit these bars to be operated without being arrested in their movement by the index pins on the movement of the operating lever 12. The

return movement of the digit or rack bars, after being uniformly operated, then resets the counter wheels to their zero position, by means described below.

The counter wheels are stopped in their zero position by'the dogs I45 which are carried by the rock shaft I45. This rock shaft is rocked by the engagementof the dog I41 provided on the extension I45 of the toggle lever III with the dog I45A so that on the depression of the key I the projections provided by the dogs I45 are then rocked against the periphery of the counter wheels and stop the wheels when their lugs I45 provided on the periphery of the counter wheels make contact therewith.

' When a counter wheel is rotated more than one revolution the amount of one revolution of this counter wheel is carried over to the digit bar of the next succeeding counter wheel. This is done by the swinging latches I49 which are mounted to swing on the pivot shaft I35. Such a latch is provided for all but the last of'the counter wheels. The lower ends of the swinging latches normally rest against the periphery of the counter wheels and when one of them is rotated more than one revolution, the lug I45 provided on the periphery of the counter wheel, rocks the latch and forces the upper end of the latch away from the upper ends of the digit or rack bar of the nextsucceedlng counter wheel in order to allow the digit or rack bar to move up higher during its return movement and rotate the counter wheel an extra tenth of a revolution to carry over and add to this counter wheel the amount of a complete revolution of the previous counter wheel.

The upper end of the latches I49 are locked away from the top of the digit bars by means of the spring latches I50 which engage into the notch II when the latches are rocked as above described.

After the next set up of an amount and the operation of the operating lever to move the car.- riage 15 down previous to the movement of the counter wheels by the digit or rack bars, the

latches I45 areswung back to their normal position by the horizontalresetting bar I52. This resetting bar is located in front of the upper portion of the latches I45 and is supported and mounted to swing on the pivot shaft I55 by means of the arms I53 and I54. A link I55 is attached to the inside of the resetting bar and connects this bar to one end of the bell crank I 55. A slotted link I51 (see Figure 4) is pivoted to the other end of the bell crank I55 and into the slot of this link projects the stud I55 carried by the carriage 15. The length of the slot in the link I51 is such that on the last portion of the downward movement of the carriage 15 by the operating lever 12, the stud I55 draws the link I51 with it and rocks the bell crank I55 which In turn draws the link I55 to the left in figure 2 and rocks the resetting bar toward the digit bars so that the upper portion of any of the latches I45 which have been previously swung away from the digit bars are forced back to have the hook I55 overhang the top of the digit bar and provide a stop for it. In the latter position the spring latch I55 engages the notch I5I to hold the latch yieldingly locked in this position while the resetting bar I52 is swung back to its starting position.

The index pin carriage "55 has a handle I42 projecting to the front of the calculating attachment. This handle is provided with a pointer I45 which projects upwardly from the handle and indicates the position of the carriage during its operation on the column indicator I44. The handle I42 is provided for the purpose'of Erasing any amount set up by the keys before the operating handle is operated. This is done by simply shifting the carriage 55 back to its starting position by pushing the handle I42 to the right in Figure 1.

For the purpose of locking the counter wheels in engaged or in disengaged position relative to the digit or rack bars, the end of the counter shaft I21 carries the locking arm I52. This arm projects thru the vertical base plate I. and its free end is suspended by means of the spring I55 to have the lug I 54 thereof engage into either the notch I55 or I55 provided in the fixed latch plate I51. 7 The free end of the locking arm overhangs the locking cam I55 carried on the shaft 5i. This cam is so positioned on the shaft that the cut away portion of it is normally located at the top at the beginning of the movement of the carriage 15. The locking arm I52 is thus free to be drawn to the right in Figure 3 on the swinging of the counter shaft to move the counter wheels out of mesh with the digit rack bars on the first part of the rotation of the shaft 51 and moves the lug I54 of the locking arm into engagement with the notch I55 in the latch plate I51. The locking cam then engages the under side of the locking arm and holds the lug I54 locked in place in the notch I55 of the latch plate until the shaft 5i and cam I55 has made a complete revolution during the downward movement of the carriage 15. A detent 250 supported on the casing and projecting in close proximity to the periphery of each of the numeral wheels so as to engage the lugs I45 thereof, serve to align the numeral wheels and prevent their rotation when disengaged from 'the racks. At the end of the revolution of the shaft and cam, the cut away portion is again located under the end of the locking arm and this permits the countershaft to be moved to the left to bring the counter wheels in mesh with the digit rack bars for the operation of the counter wheels by the digit rack bars on their upward return movement. The counter shaft I21 when it is swung back moves the locking arm to the left in Figure 5 to have the lug I54 thereof move out of the notch I55 into the notch I55 of the latch plate I61. The rotation of the shaft 81 and the cam I68 on the upward return movement of the carriage 16, then locks the locking -arm against the latch plate to hold the counter wheels locked in mesh with the digit rack bars.

From the foregoing it will be apparent that I have devised a new and useful calculating attachment for typewriterswhich embodies the features enumerated in the statement of the invention and the above description and, while I have in the present instance shown and described preferred embodiments thereof which will give in practice satisfactory and reliable results, it is to be understood that these embodiments are susceptible of modification in various particulars without departing from the spirit or the scope of the invention or sacrificing any of its advantages.

The attachment does not impair in any way the operation of the typewriter as such and the recording of the amounts set up on the calculating attachment may be done at any point on the typewriter platen F.

I claim:

1. A combined typewriting and calculating ma chine having a carriage, a platen carried by said carriage and a type operating mechanism cooperating with said carriage, a calculating mechanism, keys for operating said type'operating mechanism and carriage, keys for setting up said calculating mechanism and connecting means for connecting said type operating keys with said calculating mechanism set up keys, to simultaneously operate both said type operating mechanism and said calculating mechanism on the operation of said type operating keys, an operating lever for registering each set up on said calculating mechanism and means operated by said operating lever to disengage said connecting means between said type operating keys and calculating mechanism set up keys.

2. In a calculating attachment for typewriters having numeral keys, the combination of a keyboard having substantially vertical key stems, a registering mechanism, connecting members carried by said key stems, shifting means for moving said connecting members into engagement. with said numeral keys, an operating lever for causing the operation of said registering mechanism, and means moved by said operating lever to operate said shifting means so as to disconnect said connecting members from said numeral keys.

3. In a calculating attachment for typewriters having numeral keys, the combination of a keyboard having substantially vertical key stems forming cam slides, a registering mechanism, connecting members carried by said cam slides, shifting means for moving said connecting members into engagement with said numeral keys, an operating lever for causing the operation of said registering mechanism, an extension arm pivoted on one end of said shifting meanacam means carried by said operating lever and adapted to engage and move said extension arm in one direction on the operation of said operating lever so as to operate said shifting means to disconnect said connecting means from said numeral keys.

4. A combined typewriting and calculating machine having a movable carriage, a platen carried by said carriage and a stationary type operating mechanism cooperating with said carriage, a calculatingmechanism, keys for operating said type operating mechanism and carriage,

keys for indexing said calculating mechanism, connecting means for engaging said type operating keys with said calculating mechanism op erating keys to jointly operate said calculating operating keys with said type operating keys on the operation of said type operating keys, an operating lever for said calculating mechanism, and disconnecting means operated by said operating lever of said calculating mechanism for disconnecting said type operating keys from said calculating mechanism operating keys on the operation of said calculating mechanism by said operating lever.

5. A combined typewriting and calculating machine having a movable carriage, a platen carried by said carriage and a type operating mechanism cooperating with said carriage, a key board for operating said type operating mechanism and carriage, a second key board for indexing said calculating mechanism, means for supporting said calculating mechanism key board in a predetermined position with relation to said typewriter key board and for supporting said calculating mechanism to one side of said key board and detachable connecting means connecting the keys of said type operating key board with the keys of said calculating mechanism key board, an operating lever for said calculating mechanism and means operated by said operating lever of said calculating mechanism for operating said detachable connecting means to disconnect said type operating key board from said calculating mechanism key board.

6. The combination with a typewriter having a series of numeral keys, of a calculating machine attachment having a keyboard, connecting means connecting said numeral keys of said typewriter with said calculating machine keyboard to enable an operation of said calculating machine key board by said numeral keys, a calculating mechanism, and an operating lever for said calculating mechanism, said connecting means between said numeral keys and said calculating machine keyboard being disconnected by the operation of said lever.

'7. In a calculating attachment for attachment to typewriters having numeral keys with a registering mechanism embodied in the calculating attachment the combination of a supporting member mounted on the front of the typewriter, a keyboard carriedby said supporting member, connecting means connecting said keyboard with said numeral keys and means for operating said connecting means to disengage said connecting means from said numeral keys on the operation of said registering mechanism.

8. In a combined calculating and typewriting machine including a registering mechanism the combination of a keyboard for said typewriting machine, a keyboard for setting up said registering mechanism, said second keyboard being vertically in line with the numeral keys of said typewriting machine keyboard, a shifting bar extending from one side of said keyboard to the other side thereof, keyboard connecting means carried by said shift bar, a lever at one end of said shift bar for moving said shift bar to have said connecting means connect the keyboard of said typewriting machine with the keyboard of said calculating machine, and an operating lever for operating said shift par and causing said connecting means to disconnect said keyboards.

CHARLES H. SAMPSON. 

